Process for producing highly flowable propylene polymer and highly flowable propylene polymer

ABSTRACT

A propylene polymer can be produced which has evenness of composition and regulated stereoregularity and is highly flowable and highly flexible. Also provided is propylene-based modifier giving a molding which is soft, reduced in tackiness, and excellent in compatibility with polyolefin resins. Furthermore, provided is a hot-melt adhesive composition. It is excellent in heat resistance and flowability at high temperature and in adhesion to lowly polar substance. It is usable for sanitary materials, packing, bookbinding, fibers, woodworking, electric materials, canmaking, building, bagmaking, etc.

TECHNICAL FIELD

The present invention relates to a process for producing a highlyflowable propylene-based polymer, the propylene-based polymer, amodifier made of the propylene-based polymer, and a hot-melt adhesivecomposition containing the propylene-based polymer.

The propylene-based polymer that is produced by the production method ofthe present invention is suitably used in various applications such ashot-melt adhesives, sealing agents, modifiers for resins and elastomers,wax blending agents and filler blending agents.

Also, the hot-melt adhesive composition of the present invention isexcellent in heat resistance and flowability under a high-temperaturecondition as well as adhesion to low-polar substances.

BACKGROUND ART

Hitherto, as polymers that have relatively low molecular weight andcrystallinity and are usable as hot-melt adhesives, etc., there areknown propylene homopolymers or olefin-based polymers produced bycopolymerizing a propylene-based compound with ethylene or propylene.

However, these polymers tend to be deteriorated in uniformity due tobroad molecular weight distribution and broad composition distributionthereof.

In addition, there are also known non-crystalline poly-α-olefins.However, the non-crystalline poly-α-olefins tend to have broad molecularweight distribution and composition distribution and be ill-balancedbetween flowability, physical property (elastic modulus) andfabricability (melting point).

Meanwhile, conventionally, propylene polymers have been produced usingmagnesium-supported titanium catalysts (Japanese Patent ApplicationLaid-Open No. Hei 7-145205). However, the thus produced propylenepolymers have a non-uniform composition which gives adverse influenceson properties thereof such as occurrence of stickiness and poortransparency.

In this regard, in recent years, propylene polymers having a uniformcomposition and a relatively low molecular weight have been producedusing metallocene catalysts.

For example, WO 01/96490 discloses resins for polyolefin-based hot-meltadhesives which are made of propylene-based polymers produced in thepresence of the metallocene catalysts.

Specifically, as the polymerization catalysts for production of thepropylene-based polymers, there are disclosed polymerization catalystscomposed of a transition metal compound used as the component (A) in thepresent invention and a co-catalyst selected from the group consistingof a compound capable of forming an ionic complex by reacting with thecomponent (A), and aluminoxane.

In the above prior publication, only the aluminoxane has been concretelyused in Examples thereof, and the propylene-based polymers produced havea uniform composition and a relatively low molecular weight. However,the polymerization activity of the catalyst used therein is notnecessarily high.

Further, in the above catalyst system, since the influence of hydrogenon the molecular weight is not large and the catalytic activity thereofunder a high polymerization temperature condition is not necessarilyhigh, it will be difficult to sufficiently reduce the molecular weightof the propylene-based polymers.

More specifically, the propylene homopolymers specifically disclosed inthe prior publication have an intrinsic viscosity [η] as high as about0.5 dL/g.

Also, hot-melt adhesives used in hot-melt bonding methods in whichhigh-molecular compounds are heat-melted for bonding, have beenextensively employed in various applications because they are excellentin high-speed coatability, rapid curability, solvent-free applicability,barrier property, energy-saving property, inexpensiveness, etc.

The conventional hot-melt adhesives are mainly composed of resinsprepared by blending a tackifier resin or a plasticizer in a basepolymer such as natural rubbers, ethylene-vinyl acetate copolymers,styrene-butadiene-styrene block copolymers and styrene-isoprene-styreneblock copolymers.

However, since the above base polymers contain a large amount of doublebonds, the resins for hot-melt adhesives which are formulated using suchbase polymers, exhibit a poor thermal stability upon heating and,therefore, suffer from oxidation, gelation, decomposition anddiscoloration upon coating. In addition, there occurs such a problemthat portions bonded by the hot-melt adhesives tend to be deterioratedin strength with time.

Further, the hot-melt adhesives are also deteriorated in adhesion tolow-polar substances such as polyethylene and polypropylene.

To solve the deteriorated adhesion to low-polar substances, there havebeen conventionally used hot-melt adhesive resins containingpolypropylene as a base polymer. These resins show a good thermalstability, but are deteriorated in flowability due to a too highhardness of the base polymer contained therein. As a result, thehot-melt adhesive resins must be applied under a high temperaturecondition, so that there occurs such a problem that the thermalstability of the resins becomes lowered under such a high-temperaturecondition and, therefore, a sufficient adhesion strength cannot beattained.

In order to solve the above problems and defects of the conventionalhot-melt adhesive resins, the present inventors have proposed, inJapanese Patent Application No. 2000-178420, polyolefin-based hot-meltadhesive resins that are excellent in thermal stability and flowabilityunder a high-temperature condition, adhesion to low-polar substances,and heat resistance at a bonded surface formed thereby.

However, it has been further demanded to develop propylene-basedpolymers having a still higher flowability as well as a process forproduction thereof which can be performed with a high activity,especially a high sensitivity to hydrogen.

Further, it has also been demanded to develop hot-melt adhesivecompositions using the highly flowable propylene-based polymers whichare reduced in amount of a viscosity modifier blended, and are excellentin balance between flowability and adhesion property, and adhesion tolow-polar substances.

The present invention has been made to solve the above conventionalproblems. An object of the present invention is to provide a process forefficiently producing a highly flowable crystalline propylene-basedpolymer having a uniform composition and a well-controlledstereoregularity, the propylene-based polymer, a modifier made of thepropylene-based polymer, and a hot-melt adhesive composition containingthe propylene-based polymer.

DISCLOSURE OF THE INVENTION

As a result of extensive researches for accomplishing the above object,the inventors have found that the propylene-based polymers can beproduced at a considerably high activity in the presence of apolymerization catalyst composed of (A) a specific transition metalcompound and (B) an organoboron compound, as compared to the case wherealuminoxane is used as the component (B), and the resultantpropylene-based polymers can exhibit suitable molecular weightdistribution and composition distribution as well as a well-controlledbalance between flowability, physical property (elastic modulus) andfabricability (melting point).

In addition, the inventors have found that the above propylene-basedpolymers can provide a hot-melt adhesive composition which is reduced inamount of a viscosity modifier blended, and is excellent in balancebetween flowability and adhesion property, and adhesion to low-polarsubstances.

The present invention has been accomplished based on the above findings.

Thus, the present invention provides a process for producing apropylene-based polymer, the propylene-based polymer, a modifier made ofthe propylene-based polymer, and a hot-melt adhesive compositioncontaining the propylene-based polymer and a tackifier as describedbelow.

1. A process for producing a highly flowable propylene-based polymer,comprising:

-   -   polymerizing propylene in the presence of a polymerization        catalyst comprising:    -   (A) a transition metal compound represented by the following        general formula (I):        wherein M is a metal element belonging to Groups 3 to 10 or        lanthanoid of the Period Table;    -   E¹ and E² are independently a ligand selected from the group        consisting of substituted cyclopentadienyl, indenyl, substituted        indenyl, heterocyclopentadienyl, substituted        heterocyclopentadienyl, amide group, phosphide group,        hydrocarbon groups and silicon-containing groups, which form a        cross-linked structure via A¹ and A² and may be same or        different from each other;    -   X is a ligand capable of forming a σ-bond with the proviso that        when a plurality of X groups are present, these X groups may be        same or different from each other, and may be cross-linked with        the other X group, E¹, E² or Y;    -   Y is a Lewis base with the proviso that when a plurality of Y        groups are present, these Y groups may be same or different from        each other, and may be cross-linked with the other Y group, E¹,        E² or X;    -   A¹ and A² are divalent cross-linking groups capable of bonding        the two ligands E¹ and E² to each other which may be same or        different from each other, and are independently a C₁ to C₂₀        hydrocarbon group, a C₁ to C₂₀ halogen-containing hydrocarbon        group, a silicon-containing group, a germanium-containing group,        a tin-containing group, —O—, —CO—, —S—, —SO₂—, —Se—, —NR¹—,        —PR¹—, —P(O)R¹—, —BR¹— or —AlR¹— wherein R¹ is a hydrogen atom,        a halogen atom, a C₁ to C₂₀ hydrocarbon group or a C₁ to C₂₀        halogen-containing hydrocarbon group;    -   q is an integer of 1 to 5 given by the formula:        [(valence of M)−2]; and    -   r is an integer of 0 to 3, and    -   (B) an organoboron compound.

2. A process for producing a highly flowable propylene-based polymer,comprising:

-   -   copolymerizing propylene with ethylene and/or a C₄ to C₂₀        α-olefin in the presence of a polymerization catalyst        comprising:

(A) a transition metal compound represented by the following generalformula (I):

wherein M is a metal element belonging to Groups 3 to 10 or lanthanoidof the Period Table;

-   -   E¹ and E² are independently a ligand selected from the group        consisting of substituted cyclopentadienyl, indenyl, substituted        indenyl, heterocyclopentadienyl, substituted        heterocyclopentadienyl, amide group, phosphide group,        hydrocarbon groups and silicon-containing groups, which form a        cross-linked structure via A¹ and A² and may be same or        different from each other;    -   X is a ligand capable of forming a α-bond with the proviso that        when a plurality of X groups are present, these X groups may be        same or different from each other, and may be cross-linked with        the other X group, E¹, E² or Y;    -   Y is a Lewis base with the proviso that when a plurality of Y        groups are present, these Y groups may be same or different from        each other, and may be cross-linked with the other Y group, E¹,        E² or X;    -   A¹ and A² are divalent cross-linking groups capable of bonding        the two ligands E¹ and E² to each other which may be same or        different from each other, and are independently a C₁ to C₂₀        hydrocarbon group, a C₁ to C₂₀ halogen-containing hydrocarbon        group, a silicon-containing group, a germanium-containing group,        a tin-containing group, —O—, —Co—, —S—, —SO₂—, —Se—, —NR¹—,        —PR¹—, —P(O)R¹—, —BR¹— or —AlR¹— wherein R¹ is a hydrogen atom,        a halogen atom, a C₁ to C₂₀ hydrocarbon group or a C₁ to C₂₀        halogen-containing hydrocarbon group;    -   q is an integer of 1 to 5 given by the formula:

[(valence of M)-2]; and

-   -   r is an integer of 0 to 3, and (B) an organoboron compound.

3. A highly flowable propylene-based polymer satisfying the followingrequirements (1), (2) and (3):

-   -   (1) an intrinsic viscosity [η] of 0.01 to 0.5 dL1 g as measured        in a tetralin solvent at 135° C.;    -   (2) a crystalline resin having a melting point (Tm−D) of 0 to        120° C., the melting point being defined as a top of a peak        observed on a highest-temperature side in a melting endothermic        curve obtained by a differential scanning calorimeter (DSC) when        a sample is held in a nitrogen atmosphere at −10° C. for 5 min        and then heated at a temperature rise rate of 10° C./min; and    -   (3) a stereoregularity index ([mm]) of 50 to 90 mol %.

4. A highly flowable propylene-based polymer according to the aboveaspect 3, satisfying the following requirements (1′), (2′) and (3′):

-   -   (1′) an intrinsic viscosity [η] of 0.1 to 0.4 dL/g as measured        in a tetralin solvent at 135° C.;    -   (2′) a crystalline resin having a melting point (Tm−D) of 60 to        120° C., the melting point being defined as a top of a peak        observed on a highest-temperature side in a melting endothermic        curve obtained by a differential scanning calorimeter (DSC) when        a sample is held in a nitrogen atmosphere at −10° C. for 5 min        and then heated at a temperature rise rate of 10° C./min; and    -   (3′) a mesopentad fraction (mmmm) of 30 to 60 mol %.

5. The highly flowable propylene-based polymer according to the aboveaspect 3 or 4, wherein said polymer further satisfies the followingrequirements (4) and (5):

-   -   (4) a molecular weight distribution (Mw/Mn) of 4 or lower as        measured by gel permeation chromatography (GPC); and    -   (5) a weight-average molecular weigh of 10,000 to 100,000 as        measured by GPC.    -   6. A propylene-based modifier comprising the highly flowable        propylene-based polymer as described in the above aspect 3.    -   7. A hot-melt adhesive composition comprising 99 to 50% by        weight of the highly flowable propylene-based polymer as        described in the above aspect 3 or 4, and 50 to 1% by weight of        a tackifier.

BEST MODE FOR CARRYING OUT THE INVENTION

In the following descriptions, [1] the process for producing thepropylene-based polymer, [2] the propylene-based polymer, [3] thepropylene-based modifier and [4] the hot-melt adhesive composition areexplained in detail.

[1] Process for Production of Propylene-Based Polymer

In the process for production of the propylene-based polymer accordingto the present invention, the propylene-based polymer is produced by (a)homopolymerizing propylene, or (a′) copolymerizing propylene withethylene and/or a C₄ to C₂₀ α-olefin, in the presence of apolymerization catalyst comprising:

(A) a transition metal compound represented by the following generalformula (I):

wherein M is a metal element belonging to Groups 3 to 10 or lanthanoidof the Period Table;

-   -   E¹ and E² are independently a ligand selected from the group        consisting of substituted cyclopentadienyl, indenyl, substituted        indenyl, heterocyclopentadienyl, substituted        heterocyclopentadienyl, amide group, phosphide group,        hydrocarbon groups and silicon-containing groups, which form a        cross-linked structure via A¹ and A² and may be same or        different from each other;    -   X is a ligand capable of forming a α-bond with the proviso that        when a plurality of X groups are present, these X groups may be        same or different from each other, and may be cross-linked with        the other X group, E¹, E² or Y;    -   Y is a Lewis base with the proviso that when a plurality of Y        groups are present, these Y groups may be same or different from        each other, and may be cross-linked with the other Y group, E¹,        E² or X;    -   A¹ and A² are divalent cross-linking groups capable of bonding        the two ligands E¹ and E² to each other which may be same or        different from each other, and are independently a C₁ to C₂₀        hydrocarbon group, a C₁ to C₂₀ halogen-containing hydrocarbon        group, a silicon-containing group, a germanium-containing group,        a tin-containing group, —O—, —CO—, —S—, —SO₂—, —Se—, —NR¹—,        —PR¹—, —P(O)R¹—, —BR¹— or —AlR¹— wherein R¹ is a hydrogen atom,        a halogen atom, a C₁ to C₂₀ hydrocarbon group or a C₁ to C₂₀        halogen-containing hydrocarbon group;    -   q is an integer of 1 to 5 given by the formula:        [(valence of M)−2]; and    -   r is an integer of 0 to 3, and    -   (B) an organoboron compound.

In the above general formula (I), M represents a metal element belongingto Groups 3 to 10 or lanthanoid of the Period Table. Specific examplesof the metal element M include titanium, zirconium, hafnium, yttrium,vanadium, chromium, manganese, nickel, cobalt, palladium and lanthanoidmetals. Of these metal elements, preferred are titanium, zirconium andhafnium from the standpoint of a good catalytic activity forpolymerization of olefins.

E¹ and E² are independently a ligand selected from the group consistingof substituted cyclopentadienyl, indenyl, substituted indenyl,heterocyclopentadienyl, substituted heterocyclopentadienyl, amide group(—N<), phosphide group (—P<), hydrocarbon groups (>CR—, >C<) andsilicon-containing groups (>SiR—, >Si<) wherein R is hydrogen, a C₁ toC₂₀ hydrocarbon group or a hetero atom-containing group, and form across-linked structure via A¹ and A².

The ligands E¹ and E² may be same or different from each other. Of theseligands E¹ and E², preferred are substituted cyclopentadienyl, indenyland substituted indenyl.

X represents a ligand capable of forming a α-bond. When a plurality of Xgroups are present, these X groups may be same or different from eachother, and may be respectively cross-linked with the other X group, E¹,E² or Y.

Specific examples of the ligand X include a halogen atom, a C₁ to C₂₀hydrocarbon group, C₁ to C₂₀ alkoxy, C₆ to C₂₀ aryloxy, a C₁ to C₂₀amide group, a C₁ to C₂₀ silicon-containing group, a C₁ to C₂₀ phosphidegroup, a C₁ to C₂₀ sulfide group and C₁ to C₂₀ acyl.

Y represents a Lewis base. When a plurality of Y groups are present,these Y groups may be same or different from each other, and may berespectively cross-linked with the other Y group, E¹, E² or X.

Specific examples of the Lewis base as Y include amines, ethers,phosphines and thioethers.

A¹ and A² are divalent cross-linking groups capable of bonding the twoligands to each other which may be same or different from each other,and are independently represent a C₁ to C₂₀ hydrocarbon group, a C₁ toC₂₀ halogen-containing hydrocarbon group, a silicon-containing group, agermanium-containing group, a tin-containing group, —O—, —CO—, —S—,—SO₂—, —Se—, —NR¹—, —PR¹—, —P(O)R¹—, —BR¹— or —AlR¹— wherein R¹ is ahydrogen atom, a halogen atom, a C₁ to C₂₀ hydrocarbon group or a C₁ toC₂₀ halogen-containing hydrocarbon group.

The cross-linking groups include, for example, groups represented by thefollowing general formula:

wherein D is carbon, silicon or tin; R² and R³ are independently ahydrogen atom or a C₁ to C₂₀ hydrocarbon group, and may be same ordifferent from each other and may be bonded to each other to form aring; and e is an integer of 1 to 4. Specific examples of thecross-linking groups represented by the above formula include methylene,ethylene, ethylidene, propylidene, isopropylidene, cyclohexylidene,1,2-cyclohexylene, vinylidene (CH₂═C═), dimethylsilylene,diphenylsilylene, methylphenylsilylene, dimethylgermylene,dimethylstannylene, tetramethyldisilylene and diphenyldisilylene.

Of these cross-linking groups, preferred are ethylene, isopropylideneand dimethylsilylene.

The symbol q is an integer of 1 to 5 given by the formula:[(valence of M)−2], and r is an integer of 0 to 3.

Of these transition metal compounds represented by the above generalformula (I), preferred are transition metal compounds having as aligand, a double crosslinking type biscyclopentadienyl derivativerepresented by the following general formula (II):

In the above general formula (II), M, A¹, A², q and r have the samedefinitions as described previously.

X¹ is a ligand capable of forming a σ-bond, and when a plurality of X¹groups are present, these X¹ groups may be same or different from eachother and may be respectively cross-linked with the other X¹ group orY¹.

Specific examples of the X¹ groups are the same as exemplified abovewith respect to X of the general formula (I).

Y¹ is a Lewis base, and when a plurality of Y¹ groups are present, theseY¹ groups may be same or different from each other, and may berespectively cross-linked with the other Y¹ group or X¹.

Specific examples of the Y¹ groups are the same as exemplified abovewith respect to Y of the general formula (I).

R⁴ to R⁹ are independently a hydrogen atom, a halogen atom, a C₁ to C₂₀hydrocarbon group, a C₁ to C₂₀ halogen-containing hydrocarbon group, asilicon-containing group or a hetero atom-containing group. However, atleast one of R⁴ to R⁹ should be a group other than a hydrogen atom.

Also, R⁴ to R⁹ may be same or different from each other, and adjacenttwo groups thereof may be bonded to each other to form a ring.

In particular, R⁶ and R⁷ as well as R⁸ and R⁹ are preferably bonded toeach other to form a ring.

R⁴ and R⁵ are preferably groups containing a hetero atom such as oxygen,halogen and silicon, because these groups exhibit a high polymerizationactivity.

The transition metal compound containing double crosslinking typebiscyclopentadienyl derivatives as ligands preferably contains siliconin the crosslinking group between the ligands.

Specific examples of the transition metal compounds represented by thegeneral formula (I) include(1,2′-ethylene)(2,1′-ethylene)bis(indenyl)zirconium dichloride,(1,2′-methylene)(2,1′-methylene)bis(indenyl)zirconium dichloride,(1,2′-isopropylidene)(2,1′-isopropylidene)bis(indenyl)zirconiumdichloride, (1,2′-ethylene)(2,1′-ethylene)bis(3-methylindenyl)zirconiumdichloride, (1,2′-ethylene)(2,1′-ethylene)bis(4,5-benzoindenyl)zirconiumdichloride,(1,2′-ethylene)(2,1′-ethylene)bis(4-isopropylindenyl)zirconiumdichloride,(1,2′-ethylene)(2,1′-ethylene)bis(5,6-dimethylindenyl)zirconiumdichloride,(1,2′-ethylene)(2,1′-ethylene)bis(4,7-diisopropylindenyl)zirconiumdichloride, (1,2′-ethylene)(2,1′-ethylene)bis(4-phenylindenyl)zirconiumdichloride,(1,2′-ethylene)(2,1′-ethylene)bis(3-methyl-4-isopropylindenyl)zirconiumdichloride, (1,2′-ethylene)(2,1′-ethylene)bis(5,6-benzoindenyl)zirconiumdichloride, (1,2′-ethylene)(2,1′-isopropylidene)bis(indenyl)zirconiumdichloride, (1,2′-methylene) (2,1′-ethylene)bis(indenyl)zirconiumdichloride, (1,2′-methylene)(2,1′-isopropylidene)bis(indenyl)zirconiumdichloride,(1,2′-dimethylsilylene)(2,1′-dimethylsilylene)bis(indenyl)zirconiumdichloride,(1,2′-dimethylsilylene)(2,1′-dimethylsilylene)bis(3-methylindenyl)zirconiumdichloride, (1,2′-dimethylsilylene)(2,1′-dimethylsilylene)bis(3-n-butylindenyl)zirconium dichloride,(1,2′-dimethylsilylene)(2,1′-dimethylsilylene)bis(3-1-propylindenyl)zirconiumdichloride,(1,2′-dimethylsilylene)(2,1′-dimethylsilylene)bis(3-trimethylsilylmethylindenyl)zirconiumdichloride,(1,2′-dimethylsilylene)(2,1′-dimethylsilylene)bis(3-phenylindenyl)zirconiumdichloride,(1,2′-dimethylsilylene)(2,1′-dimethylsilylene)bis(4,5-benzoindenyl)zirconiumdichloride,(1,2′-dimethylsilylene)(2,1′-dimethylsilylene)bis(4-isopropylindenyl)zirconiumdichloride,(1,2′-dimethylsilylene)(2,1′-dimethylsilylene)bis(5,6-dimethylindenyl)zirconiumdichloride,(1,2′-dimethylsilylene)(2,1′-dimethylsilylene)bis(4,7-di-1-propylindenyl)zirconiumdichloride,(1,2′-dimethylsilylene)(2,1′-dimethylsilylene)bis(4-phenylindenyl)zirconiumdichloride,(1,2′-dimethylsilylene)(2,1′-dimethylsilylene)bis(3-methyl-4-1-propylindenyl)zirconiumdichloride,(1,2′-dimethylsilylene)(2,1′-dimethylsilylene)bis(5,6-benzoindenyl)zirconiumdichloride,(1,2′-dimethylsilylene)(2,1′-isopropylidene)bis(indenyl)zirconiumdichloride,(1,2′-dimethylsilylene)(2,1′-isopropylidene)bis(3-methylindenyl)zirconiumdichloride,(1,2′-dimethylsilylene)(2,1′-isopropylidene)bis(3-1-propylindenyl)zirconiumdichloride,(1,2′-dimethylsilylene)(2,1′-isopropylidene)bis(3-n-butylindenyl)zirconiumdichloride,(1,2′-dimethylsilylene)(2,1′-isopropylidene)bis(3-trimethylsilylmethylindenyl)zirconiumdichloride,(1,2′-dimethylsilylene)(2,1′-isopropylidene)bis(3-trimethylsilylindenyl)zirconiumdichloride, (1,2′-dimethylsilylene)(2,1′-isopropylidene)bis(3-phenylindenyl)zirconium dichloride,(1,2′-dimethylsilylene)(2,1′-methylene)bis(indenyl)zirconium dichloride,(1,2′-dimethylsilylene)(2,1′-methylene)bis(3-methylindenyl)zirconiumdichloride, (1,2′-dimethylsilylene)(2,1′-methylene)bis(3-1-propylindenyl)zirconium dichloride,(1,2′-dimethylsilylene)(2,1′-methylene)bis(3-n-butylindenyl)zirconiumdichloride,(1,2′-dimethylsilylene)(2,1′-methylene)bis(3-trimethylsilylmethylindenyl)zirconiumdichloride, (1,2′-dimethylsilylene)(2,1′-methylene)bis(3-trimethylsilylindenyl)zirconium dichloride,(1,2′-diphenylsilylene)(2,1′-methylene)bis(indenyl)zirconium dichloride,(1,2′-diphenylsilylene)(2,1′-methylene)bis(3-methylindenyl)zirconiumdichloride,(1,2′-diphenylsilylene)(2,1′-methylene)bis(3-1-propylindenyl)zirconiumdichloride,(1,2′-diphenylsilylene)(2,1′-methylene)bis(3-n-butylindenyl)zirconiumdichloride, (1,2′-diphenylsilylene)(2,1′-methylene)bis(3-trimethylsilylmethylindenyl)zirconium dichloride,(1,2′-diphenylsilylene)(2,1′-methylene)bis(3-trimethylsilylindenyl)zirconiumdichloride, (1,2′-dimethylsilylene) (2,1′-dimethylsilylene)(3-methylcyclopentadienyl) (3′-methylcyclopentadienyl)zirconiumdichloride,(1,2′-dimethylsilylene)(2,1′-isopropylidene)(3-methylcyclopentadienyl)(3′-methylcyclopentadienyl)zirconium dichloride, (1,2′-dimethylsilylene)(2,1′-ethylene)(3-methylcyclopentadienyl)(3′-methylcyclopentadienyl)zirconium dichloride,(1,2′-ethylene)(2,1′-methylene)(3-methylcyclopentadienyl)(3′-methylcyclopentadienyl)zirconium dichloride,(1,2′-ethylene)(2,1′-isopropylidene)(3-methylcyclopentadienyl)(3′-methylcyclopentadienyl)zirconium dichloride,(1,2′-methylene)(2,1′-methylene)(3-methylcyclopentadienyl)(3′-methylcyclopentadienyl)zirconium dichloride,(1,2′-methylene)(2,1′-isopropylidene)(3-methylcyclopentadienyl)(3′-methylcyclopentadienyl)zirconium dichloride,(1,2′-isopropylidene)(2,1′-isopropylidene) (3-methylcyclopentadienyl)(3′-methylcyclopentadienyl)zirconium dichloride,(1,2′-dimethylsilylene)(2,1′-dimethylsilylene)(3,4-dimethylcyclopentadienyl)(3′,4′-dimethylcyclopentadienyl)zirconium dichloride,(1,2′-dimethylsilylene)(2,1′-isopropylidene)(3,4-dimethylcyclopentadienyl)(3′,4′-dimethylcyclopentadienyl)zirconium dichloride,(1,2′-dimethylsilylene)(2,1′-ethylene)(3,4-dimethylcyclopentadienyl)(3′,4′-dimethylcyclopentadienyl)zirconium dichloride,(1,2′-ethylene)(2,1′-methylene)(3,4-dimethylcyclopentadienyl)(3′,4′-dimethylcyclopentadienyl)zirconium dichloride,(1,2′-ethylene)(2,1′-isopropylidene)(3,4-dimethylcyclopentadienyl)(3′,4′-dimethylcyclopentadienyl)zirconium dichloride,(1,2′-mehylene)(2,1′-methylene)(3,4-dimethylcyclopentadienyl)(3′,4′-dimethylcyclopentadienyl)zirconium dichloride, (1,2′-methylene)(2,1′-isopropylidene)(3,4-dimethylcyclopentadienyl)(3′,4′-dimethylcyclopentadienyl)zirconium dichloride,(1,2′-isopropylidene)(2,1′-isopropylidene)(3,4-dimethylcyclopentadienyl)(3′,4′-dimethylcyclopentadienyl)zirconium dichloride,(1,2′-dimethylsilylene)(2,1′-dimethylsilylene)(3-methyl-5-ethylcyclopentadienyl)(3′-methyl-5′-ethylcyclopentadienyl)zirconium dichloride,(1,2′-dimethylsilylene)(2,1′-dimethylsilylene)(3-methyl-5-ethylcyclopentadienyl)(3′-methyl-5′-ethylcyclopentadienyl)zirconium dichloride,(1,2′-dimethylsilylene)(2,1′-dimethylsilylene)(3-methyl-5-isopropylcyclopentadi enyl)(3′-methyl-5′-isopropylcyclopentadienyl)zirconium dichloride,(1,2′-dimethylsilylene)(2,1′-dimethylsilylene)(3-methyl-5-n-butylcyclopentadien yl)(3′-methyl-5′-n-butylcyclopentadienyl)zirconium dichloride,(1,2′-dimethylsilylene)(2,1′-dimethylsilylene)(3-methyl-5-phenylcyclopentadienyl) (3′-methyl-5′-phenylcyclopentadienyl)zirconium dichloride,(1,2′-dimethylsilylene)(2,1′-isopropylidene)(3-methyl-5-ethylcyclopentadienyl)(3′-methyl-5′-ethylcyclopentadienyl)zirconium dichloride,(1,2′-dimethylsilylene)(2,1′-isopropylidene)(3-methyl-5-i-propylcyclopentadienyl)(3′-methyl-5′-1-propylcyclopentadienyl)zirconium dichloride,(1,2′-dimethylsilylene)(2,1′-isopropylidene)(3-methyl-5-n-butylcyclopentadienyl)(3′-methyl-5′-n-butylcyclopentadienyl)zirconium dichloride,(1,2′-dimethylsilylene)(2,1′-isopropylidene)(3-methyl-5-phenylcyclopentadienyl)(3′-methyl-5′-phenylcyclopentadienyl)zirconium dichloride,(1,2′-dimethylsilylene)(2,1′-ethylene)(3-methyl-5-ethylcyclopentadienyl)(3′-methyl-5′-ethylcyclopentadienyl)zirconium dichloride,(1,2′-dimethylsilylene)(2,1′-ethylene)(3-methyl-5-i-propylcyclopentadienyl)(3′-methyl-5′-1-propylcyclopentadienyl)zirconium dichloride,(1,2′-dimethylsilylene)(2,1′-ethylene)(3-methyl-5-n-butylcyclopentadienyl)(3′-methyl-5′-n-butylcyclopentadienyl)zirconium dichloride,(1,2′-dimethylsilylene)(2,1′-ethylene)(3-methyl-5-phenylcyclopentadienyl)(3′-methyl-5′-phenylcyclopentadienyl)zirconium dichloride,(1,2′-dimethylsilylene)(2,1′-methylene)(3-methyl-5-ethylcyclopentadienyl)(3′-methyl-5′-ethylcyclopentadienyl)zirconium dichloride,(1,2′-dimethylsilylene)(2,1′-methylene)(3-methyl-5-i-propylcyclopentadienyl)(3′-methyl-5′-i-propylcyclopentadienyl)zirconium dichloride,(1,2′-dimethylsilylene)(2,1′-methylene)(3-methyl-5-n-butylcyclopentadienyl)(3′-methyl-5′-n-butylcyclopentadienyl)zirconium dichloride,(1,2′-dimethylsilylene)(2,1′-methylene)(3-methyl-5-phenylcyclopentadienyl)(3′-methyl-5′-phenylcyclopentadienyl)zirconium dichloride,(1,2′-ethylene)(2,1′-methylene) (3-methyl-5-i-propylcyclopentadienyl)(3′-methyl-5′-1-propylcyclopentadienyl)zirconium dichloride,(1,2′-ethylene)(2,1′-isopropylidene)(3-methyl-5-i-propylcyclopentadienyl)(3′-methyl-5′-1-propylcyclopentadienyl)zirconium dichloride,(1,2′-methylene)(2,1′-methylene)(3-methyl-5-i-propylcyclopentadienyl)(3′-methyl-5′-1-propylcyclopentadienyl)zirconium dichloride,(1,2′-methylene)(2,1′-isopropylidene)(3-methyl-5-i-propylcyclopentadienyl)(3′-methyl-5′-1-propylcyclopentadienyl)zirconium dichloride,(1,2′-diphenylsilylene) (2,1′-dimethylsilylene)bis(indenyl)zirconiumdichloride, (1,2′-diisopropylsilylene)(2,1′-dimethylsilylene)bis(indenyl)zirconium dichloride,(1,2′-diisopropylsilylene) (2,1′-diisopropylsilylene)bis(indenyl)zirconium dichloride, (1,2′-dimethylsilylene) (2,1′-dimethylsilylene)(indenyl)(3-trimethylsilylindenyl)zirconium dichloride,(1,2′-diphenylsilylene) (2,1′-diphenylsilylene)(indenyl)(3-trimethylsilylindenyl)zirconium dichloride,(1,2′-diphenylsilylene) (2,1′-dimethylsilylene)(indenyl)(3-trimethylsilylindenyl) zirconium dichloride,(1,2′-dimethylsilylene) (2,1′-diphenylsilylene)(indenyl)(3-trimethylsilylindenyl)zirconium dichloride,(1,2′-diisopropylsilylene) (2,1′-dimethylsilylene)(indenyl)(3-trimethylsilylindenyl)zirconium dichloride,(1,2′-dimethylsilylene) (2,1′-diisopropylsilylene)(indenyl)(3-trimethylsilylindenyl)zirconium dichloride,(1,2′-diisopropylsilylene) (2,1′-diisopropylsilylene)(indenyl)(3-trimethylsilylindenyl)zirconium dichloride,(1,2′-dimethylsilylene) (2,1′-dimethylsilylene)(indenyl)(3-trimethylsilylmethylindenyl)zirconium dichloride,(1,2′-diphenylsilylene) (2,1′-diphenylsilylene)(indenyl)(3-trimethylsilylmethylindenyl)zirconium dichloride,(1,2′-diphenylsilylene) (2,1′-dimethylsilylene)(indenyl)(3-trimethylsilylmethylindenyl)zirconium dichloride,(1,2′-dimethylsilylene) (2,1′-diphenylsilylene)(indenyl)(3-trimethylsilylmethylindenyl)zirconium dichloride,(1,2′-diisopropylsilylene) (2,1′-dimethylsilylene)(indenyl)(3-trimethylsilylmethylindenyl)zirconium dichloride,(1,2′-dimethylsilylene) (2,1′-diisopropylsilylene)(indenyl)(3-trimethylsilylmethylindenyl)zirconium dichloride and(1,2′-diisopropylsilylene) (2,1′-diisopropylsilylene)(indenyl)(3-trimethylsilylmethylindenyl)zirconium dichloride, as well ascompounds obtained by replacing zirconium of the above-describedcompounds with titanium or hafnium, though are not limited thereto.

In addition, similar compounds containing metal elements belonging tothe other Groups or lanthanoid series may also be used in the presentinvention.

Also, in the above-described compounds, the (1,2′-) (2.1′-)substitutedcompounds may be replaced with (1,1′-) (2.2′-)substituted compounds, andpreferably with the (1,2′-) (2.1′-)substituted compounds.

Suitable organoboron compounds usable as the component (B) includecoordination complex compounds composed of an anion and a cationcontaining a plurality of groups bonded to the metal element, or Lewisacids.

As the coordination complex compounds composed of an anion and a cationcontaining a plurality of groups bonded to the metal element, there maybe used various compounds. Examples of the coordination complexcompounds suitably used in the present invention include those compoundsrepresented by the following general formulae (III) and (IV):([L¹−H]^(s+))_(t)([M²Z²Z³ . . . Z^(n)](n−m)−)₁  (III)([L²]^(s+))_(t)([M³Z²Z³ . . . Z^(n)]^((n−m)−)) ₁  (IV)wherein L² represents M⁴, R¹⁰OR¹¹M⁵ or R¹² ₃C as defined later; L¹represents a Lewis base; M² and M³ are respectively a boron atom; M⁴ isa metal element selected from the group consisting of elements belongingto Group 1 and Groups 8 to 12 of the Periodic Table; M⁵ is a metalelement selected from the group consisting of elements belonging toGroups 8 to 10 of the Periodic Table; Z² to Zn are respectively ahydrogen atom, dialkylamino, alkoxy, aryloxy, C₁ to C₂₀ alkyl, C₆ to C₂₀aryl, alkylaryl, arylalkyl, substituted alkyl, an organometalloid groupor a halogen atom; R¹⁰ and R¹¹ are respectively cyclopentadienyl,substituted cyclopentadienyl, indenyl or fluorenyl; R¹² is alkyl; mrepresents a valence of M² or M³ and is an integer of 1 to 7; n is aninteger of 2 to 8; s represents an ionic valence of L¹—H or L² and is aninteger of 1 to 7; t is an integer of 1 or more; 1 is a number oft×s/(n−m).

M² and M³ are respectively a boron atom, and M⁴ is a metal elementselected from the group consisting of elements belonging to Group 1 andGroups 8 to 12 of the Periodic Table. Specific examples of the M⁴include respective atoms such as Ag, Cu, Na and Li. M⁵ is a metalelement selected from the group consisting of elements belonging toGroups 8 to 10 of the Periodic Table. Specific examples of the M⁵include respective atoms such as Fe, Co and Ni.

Specific examples of the Z² to Zn include dialkylamino groups such asdimethylamino and diethylamino; alkoxy groups such as methoxy, ethoxyand n-butoxy; aryloxy groups such as phenoxy, 2,6-dimethylphenoxy andnaphthyloxy; C₁ to C₂₀ alkyl groups such as methyl, ethyl, n-propyl,isopropyl, n-butyl, n-octyl and 2-ethylhexyl; C₆ to C₂₀ aryl, alkylarylor arylalkyl groups such as phenyl, p-tolyl, benzyl, pentafluorophenyl,3,5-di(trifluoromethyl)phenyl, 4-tert-butylphenyl, 2,6-dimethylphenyl,3,5-dimethylphenyl, 2,4-dimethylphenyl and 1,2-dimethylphenyl; halogenatoms such as F, Cl, Br and I; and organometalloid groups such aspentamethyl antimony, trimethylsilyl, trimethylgermyl, diphenyl arsine,dicyclohexyl antimony and diphenyl boron.

Specific examples of the substituted cyclopentadienyl groups as R¹⁰ andR¹¹ include methylcyclopentadienyl, butylcyclopentadienyl andpentamethylcyclopentadienyl.

Specific examples of the anion containing a plurality of groups bondedto the metal element include B(C₆F₅)₄ ⁻, B(C₆HF)₄ ⁻, B(C₆H₂F₃)₄ ⁻,B(C₆H₃F₂)₄ ⁻, B(C₆H₄F)₄ ⁻, B[C₆(CF₃)F₄]₄ ⁻, B(C₆H₅)₄— and BF₄ ⁻.Specific examples of the metal cation include Cp₂Fe⁺, (MeCp)₂Fe⁺,(tBuCp)₂Fe⁺, (Me₂ Cp)₂Fe⁺, (Me₃ Cp)₂Fe⁺, (Me₄ Cp)₂Fe⁺, (Me₅ Cp)₂Fe⁺,Ag⁺, Na⁺ and Li⁺. Examples of the other cations includenitrogen-containing compounds such as pyridinium,2,4-dinitro-N,N-diethyl anilinium, diphenyl ammonium, p-nitroanilinium,2,5-dichloroanilinium, p-nitro-N,N-dimethyl anilinium, quinolinium,N,N-dimethyl anilinium and N,N-diethyl anilinium; carbenium compoundssuch as triphenyl carbenium, tri(4-methylphenyl)carbenium andtri(4-methoxyphenyl)carbenium; alkyl phosphonium ions such as CH₃PH₃ ⁺,C₂H₅PH₃ ⁺, C₃H₇PH₃ ⁺, (CH₃)₂PH₂ ⁺, (C₂H₅)₂PH₂ ⁺, (C₃H₇)₂PH₂ ⁺,(CH₃)₃PH⁺, (C₂H₅)₃PH⁺, (C₃H₇)₃PH⁺, (CF₃)₃PH⁺, (CH₃)₄P⁺, (C₂H₅)₄P⁺ and(C₃H₇)₄P⁺; and aryl phosphonium ions such as C₆H₅PH₃ ⁺, (C₆H₅)₂PH₂ ⁺,(C₆H₅)₃PH⁺, (C₆H₅)₄P⁺, (C₂H₅)₂(C₆H₅)PH⁺, (CH₃)(C₆H₅)PH₂ ⁺,(CH₃)₂(C₆H₅)PH⁺ and (C₂H₅)₂(C₆H₅)₂P⁺.

In the present invention, there may be used coordination complexcompounds composed of an optional combination of the above metal cationsand anions.

Specifically, of the compounds represented by the general formulae (III)and (IV), there may be suitably used the following compounds.

Examples of the compounds represented by the general formula (III)include triethyl ammonium tetraphenylborate, tri(n-butyl)ammoniumtetraphenylborate, trimethyl ammonium tetraphenylborate, triethylammonium tetrakis(pentafluorophenyl)borate, tri(n-butyl)ammoniumtetrakis(pentafluorophenyl)borate, triethyl ammonium hexafluoroarsenate,pyridinium tetrakis(pentafluorophenyl)borate, pyrroliniumtetrakis(pentafluorophenyl)borate, N,N-dimethyl aniliniumtetrakis(pentafluorophenyl)borate and methyldiphenyl ammoniumtetrakis(pentafluorophenyl)borate.

Whereas, examples of the compounds represented by the general formula(IV) include ferrocenium tetraphenylborate, dimethyl ferroceniumtetrakis(pentafluorophenyl)borate, ferroceniumtetrakis(pentafluorophenyl)borate, decamethyl ferroceniumtetrakis(pentafluorophenyl)borate, acetyl ferroceniumtetrakis(pentafluorophenyl)borate, formyl ferroceniumtetrakis(pentafluorophenyl)borate, cyano-ferroceniumtetrakis(pentafluorophenyl)borate, silver tetraphenylborate, silvertetrakis(pentafluorophenyl)borate, trityl tetraphenylborate, trityltetrakis(pentafluorophenyl)borate and silver tetrafluoroborate.

The suitable coordination complex compounds are those compounds composedof a non-coordinated anion and a substituted triaryl carbenium. Examplesof the non-coordinated anion include anions represented by the followinggenera formula (V):(M¹Z¹Z² . . . Z^(n))^((n−m)−)  (V)wherein M¹ is a boron atom; Z¹ to Z^(n) are respectively a hydrogenatom, dialkylamino, alkoxy, aryloxy, C₁ to C₂₀ alkyl, C₆ to C₂₀ aryl(including halogen-substituted aryl), alkylaryl, arylalkyl, substitutedalkyl, an organometalloid group or a halogen atom; m is a valence of M¹;and n is an integer of 2 to 8.

Further, as the non-coordinated anion, there may be used compoundsgenerally called “carborane”.

Also, examples of the substituted triaryl carbenium include cationsrepresented by the following general formula (VI):[CR¹³R¹⁴R¹⁵]⁺  (VI)

In the above general formula (VI), R¹³, R¹⁴ and R¹⁵ are respectively anaryl group such as phenyl, substituted phenyl, naphthyl and anthracenyl,and may be same or different from each other with the proviso that atleast one of R¹³, R¹⁴ and R¹⁵ is substituted phenyl, naphthyl oranthracenyl.

Examples of the substituted phenyl group include those groupsrepresented by the following general formula (VII):C₆H_(5-k)R¹⁶ _(k)  (VII)

In the above general formula (VII), R¹⁶ is C₁ to C₁₀ hydrocarbyl,alkoxy, aryloxy, thioalkoxy, thioaryloxy, amino, amido, carboxyl or ahalogen atom; and k is an integer of 1 to 5. When k is 2 or more, aplurality of the R¹⁶ groups may be same or different from each other.

Specific examples of the non-coordinated anion represented by thegeneral formula (V) include tetra(fluorophenyl)borate,tetrakis(difluorophenyl)borate, tetrakis(trifluorophenyl)borate,tetrakis(tetrafluorophenyl)borate, tetrakis(pentafluorophenyl)borate,tetrakis(trifluoromethylphenyl)borate, tetra(toluyl)borate,tetra(xylyl)borate, [(pentafluorophenyl)triphenyl borate],[tris(pentafluorophenyl)phenyl]borate andtridecahydride-7,8-dicarbaundecaborate.

Specific examples of the substituted triaryl carbenium represented bythe above general formula (VI) include tri(toluyl)carbenium,tri(methoxyphenyl)carbenium, tri(chlorophenyl)carbenium,tri(fluorophenyl)carbenium,tri(xylyl)carbenium,[di(toluyl)phenyl]carbenium,[di(methoxyphenyl)phenyl]carbenium, [di(chlorophenyl)phenyl]carbenium,[di(phenyl)toluyl]carbenium, [di(phenyl)methoxyphenyl]carbenium and[di(phenyl)chlorophenyl]carbenium.

In addition, as the organoboron compound as the component (B) used inthe catalyst of the present invention, there may also be used compoundsrepresented by the following general formula (VIII):BR¹⁷R¹⁸R¹⁹  (VIII)wherein R¹⁷, R¹⁸ and R¹⁹ are respectively C₁ to C₂₀ alkyl or C₆ to C₂₀aryl. Namely, any of the boron compounds containing alkyl or arylsubstituent groups bonded to boron may be used as the component (B)without any particular limitations.

The alkyl group may also include halogen-substituted alkyl groups, andthe aryl group may also include halogen-substituted aryl groups andalkyl-substituted aryl groups.

Thus, R¹⁷, R¹⁸ and R¹⁹ in the above general formula (VIII) respectivelyrepresent C₁ to C₂₀ alkyl or C₆ to C₂₀ aryl. Specific examples of thealkyl and aryl groups include alkyl groups such as methyl, ethyl,propyl, butyl, amyl, isoamyl, isobutyl, octyl and 2-ethylhexyl; and arylgroups such as phenyl, fluorophenyl, tolyl, xylyl and benzyl.

Meanwhile, R¹⁷, R¹⁸ and R¹⁹ may be same or different from each other.

Specific examples of the organoboron compounds represented by the abovegeneral formula (VIII) include triphenyl boron,tri(pentafluorophenyl)boron, tri(2,3,4,5-tetrafluorophenyl)boron, tri(2,4, 5, 6-tetrafluorophenyl)boron, tri(2,3,5,6-tetrafluorophenyl)boron,tri(2,4,6-trifluorophenyl)boron, tri(3,4,5-trifluorophenyl)boron,tri(2,3,4-trifluorophenyl)boron, tri(3,4,6-trifluorophenyl)boron,tri(2,3-difluorophenyl)boron, tri(2,6-difluorophenyl)boron,tri(3,5difluorophenyl)boron, tri(2,5-difluorophenyl)boron,tri(2-fluorophenyl)boron, tri(3-fluorophenyl)boron,tri(4-fluorophenyl)boron, tri[3,5-di(trifluoromethyl)phenyl]boron,tri[(4-fluoromethyl)phenyl]boron, diethyl boron, diethylbutyl boron,trimethyl boron, triethyl boron, tri(n-butyl)boron,tri(trifluoromethyl)boron, tri(pentafluoroethyl)boron,tri(nonafluorobutyl)boron, tri(2,4,6-trifluorophenyl)boron,tri(3,5-difluorophenyl)boron, di(pentafluorophenyl)fluoroboron, diphenylfluoroboron, di(pentafluorophenyl) chloroboron, dimethyl fluoroboron,diethyl fluoroboron, di(n-butyl)fluoroboron,(pentafluorophenyl)difluoroboron, phenyl fluoroboron,(pentafluorophenyl)dichloroboron, methyl difluoroboron, ethyldifluoroboron and (n-butyl) difluoroboron.

Of these compounds, especially preferred is tri(pentafluorophenyl)boron.

The molar ratio of the component (A) to the component (B) used in thepresent invention is preferably 10:1 to 1:100 and more preferably 1:1 to1:10. If the molar ratio of the component (A) to the component (B) isout of the above-specified range, the cost performance of the catalystper unit mass of the obtained polymer is deteriorated and thereforeunpractical.

The polymerization catalyst used in the production process of thepresent invention may further contain an organoaluminum compound as thecomponent (C) in addition to the components (A) and (B).

As the organoaluminum compound (C), there may be used compoundsrepresented by the general formula (IX):R²⁰ _(v)AlJ_(3-v)  (IX)wherein R²⁰ is C₁ to C₁₀ alkyl; J is a hydrogen atom, C₁ to C₂₀ alkoxy,C₆ to C₂₀ aryl or a halogen atom; and v is an integer of 1 to 3.

Specific examples of the compounds represented by the above generalformula (IX) include trimethyl aluminum, triethyl aluminum, triisopropylaluminum, triisobutyl aluminum, dimethyl aluminum chloride, diethylaluminum chloride, methyl aluminum dichloride, ethyl aluminumdichloride, dimethyl aluminum fluoride, diisobutyl aluminum hydride,diethyl aluminum hydride and ethyl aluminum sesquichloride.

These organoaluminum compounds may be used alone or in the form of amixture of any two or more thereof.

In the production process of the present invention, the above describedcomponents (A), (B) and (C) may be preliminarily contacted with eachother.

The preliminary contact may be performed, for example, by contacting thecomponent (B) with the component (A), but is not particularly limitedand may be conducted by any known method.

The preliminary contact is effective to improve the catalytic activity,reduce the amount of the component (B) used as a co-catalyst, and reducethe costs required for the catalyst.

Also, when the components (A) and (B) are preliminarily contacted witheach other, in addition to the above effects, there can be attained suchan effect of increasing a molecular weight of the obtained polymer.

The preliminary contact temperature is usually in the range of −20 to200° C., preferably −10 to 150° C. and more preferably 0 to 80° C.

The preliminary contact may also be conducted in the presence of aninert hydrocarbon solvent such as aliphatic hydrocarbons and aromatichydrocarbons.

Of these solvents, especially preferred are aliphatic hydrocarbons.

The molar ratio of the catalyst component (A) to the catalyst component(C) is preferably in the range of from 1:1 to 1:10,000 and morepreferably from 1:5 to 1:2,500.

When further using the catalyst component (C), the resultant catalystcan be enhanced in polymerization activity per unit quantity oftransition metal used. However, the use of a too large amount of theorganoaluminum compound as the component (C) is uneconomical and rathertends to cause such a defect that a large amount of the component (C)remains in the obtained polymer.

In the present invention, at least one of the catalyst components may besupported on a suitable carrier.

The carrier usable in the present invention is not particularly limited,and may be appropriately selected from inorganic oxides, other inorganicmaterials and organic materials. Of these carriers, preferred are thosemade of inorganic oxides or other inorganic materials.

The use of the supported catalyst enables production of polymers havingan industrially useful high bulk density and an excellent particle sizedistribution.

The propylene-based polymer of the present invention can be produced byhomopolymerizing propylene, or copolymerizing propylene with ethyleneand/or C₄ to C₂₀ α-olefin, in the presence of the above polymerizationcatalyst.

Examples of the C₄ to C₂₀ α-olefins include 1-butene, 1-pentene,4-methyl-1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene,1-tetradecene, 1-hexadecene, 1-octadecene and 1-eicosene. In the presentinvention, these α-olefins may be used alone or in the form of a mixtureof any two or more thereof.

The polymerization methods usable in the present invention are notparticularly limited, and include slurry polymerization, vapor-phasepolymerization, bulk polymerization, solution polymerization, suspensionpolymerization or the like.

As to the polymerization conditions, the polymerization temperature isin the range of usually from −100 to 250° C., preferably from −50 to200° C. and more preferably from 0 to 130° C.

Also, the amounts of the reactants and the catalyst used may becontrolled such that the molar ratio of the raw monomers to the abovecomponent (A) is preferably in the range of 1 to 108 and more preferably100 to 105.

Further, the polymerization time is usually from 5 min to 10 h, and thepolymerization reaction pressure is preferably from ordinary pressure to20 MPa (gauge) and more preferably from ordinary pressure to 10 MPa(gauge).

The molecular weight of the resultant polymer may be controlled byappropriately selecting kinds and amounts of the respective catalystcomponents used and polymerization temperature, and further byconducting the polymerization in the presence of hydrogen.

Examples of solvents usable in the polymerization include aromatichydrocarbons such as benzene, toluene, xylene and ethyl benzene;alicyclic hydrocarbons such as cyclopentane, cyclohexane and methylcyclohexane; aliphatic hydrocarbons such as pentane, hexane, heptane andoctane; and halogenated hydrocarbons such as chloroform anddichloromethane.

These solvent may be used alone or in the form of a mixture of any twoor more thereof. Also, the monomers such as α-olefins may be used as thesolvent.

Meanwhile, the polymerization may also be performed in the absence of asolvent.

Prior to the substantial polymerization, a preliminary polymerizationmay be conducted using the above polymerization catalyst.

The preliminary polymerization may be conducted by contacting the solidcatalyst component with, for example, a small amount of olefins. Thecontact method is not particularly limited, and any known method may beused therefor.

Also, the olefins usable in the preliminary polymerization are notparticularly limited, and there may be used the above-described olefins,e.g., ethylene, C₃ to C₂₀ α-olefins or mixtures thereof. The olefinsused in the preliminary polymerization are preferably identical to thoseolefins used in the subsequent substantial polymerization.

The preliminary polymerization temperature is in the range of usuallyfrom −20 to 200° C., preferably from −10 to 130° C. and more preferablyfrom 0 to 80° C.

The preliminary polymerization may be conducted in the presence of anysuitable solvent such as aliphatic hydrocarbons, aromatic hydrocarbonsand other monomers.

Of these solvents, preferred are aliphatic hydrocarbons.

Also, the preliminary polymerization may be conducted in the absence ofa solvent.

The preliminary polymerization conditions may be suitably controlledsuch that the obtained preliminary polymerization reaction product hasan intrinsic viscosity [η] of 0.2 dL/g or higher as measured at 135° C.in decalin, and the yield of the preliminary polymerization reactionproduct is 1 to 10,000 g and preferably 10 to 1,000 g per one millimoleof the transition metal component contained in the catalyst.

[2] Propylene-Based Polymer

The propylene-based polymer 1 of the present invention satisfies thefollowing requirements (1) to (3).

-   -   (1) an intrinsic viscosity [η] of 0.01 to 0.5 dL/g as measured        in a tetralin solvent at 135° C.;    -   (2) a crystalline resin having a melting point (Tm−D) of 0 to        120° C., the melting point being defined as a top of a peak        observed on a highest-temperature side in a melting endothermic        curve obtained by a differential scanning calorimeter (DSC) when        a sample is held in a nitrogen atmosphere at −10° C. for 5 min        and then heated at a temperature rise rate of 10° C./min; and    -   (3) a stereoregularity index ([mm]) of 50 to 90 mol %.

The propylene-based polymer 1 of the present invention has an intrinsicviscosity [η] of 0.01 to 0.5 dL/g as measured in a tetralin solvent at135° C. The intrinsic viscosity [η] is preferably 0.1 to 0.5 dL/g andmore preferably 0.2 to 0.4 dL/g.

If the intrinsic viscosity [η] is less than 0.01 dL/g, the resultantpolymer tends to be insufficient in adhesion strength.

If the intrinsic viscosity [η] exceeds 0.5 dL/g, the resultant polymertends to be deteriorated in flowability, resulting in poor coatability.

The propylene-based polymer 1 of the present invention must be acrystalline resin having a melting point (Tm−D) of 0 to 120° C. andpreferably 0 to 100° C. as measured by differential scanning calorimeter(DSC), in view of a good softness thereof.

The melting point (Tm−D) is determined by the DSC measurement asfollows.

That is, using a differential scanning calorimeter (“DSC-7” availablefrom Perkin Elmer Corp.), 10 mg of a sample is held in a nitrogenatmosphere at −10° C. for 5 min, and then heated at a temperature riserate of 10° C./minute to prepare a melting endothermic curve. The top ofa peak observed on the highest temperature side in the meltingendothermic curve is defined as the melting point (Tm−D).

The crystalline resin used in the present invention means a resin havingthe measurable melting point (Tm−D).

In the present invention, the mesopentad fraction (mmmm) is determinedaccording to the method reported and proposed in A. Zambelli, et al.,“Macromolecules”, 6925(1973).

More specifically, the mesopentad fraction in a polypropylene a moleculeis determined by measuring signals attributed to methylene and methinegroups using ¹³C nuclear magnetic resonance spectrum.

The larger mesopentad fraction means a higher stereoregularity of thepolymer.

The ¹³C nuclear magnetic resonance spectrum measurement is carried outusing the following apparatus under the following conditions.

-   -   Apparatus: ¹³C-NMR apparatus “JNM-EX400 Model” available from        Nippon Denshi Co., Ltd.;    -   Method: proton complete decoupling method;    -   Sample concentration: 220 mg/mL;    -   Solvent: mixed solvent of 1,2,4-trichlorobenzene and heavy        benzene (volume ratio: 90:10);    -   Measuring temperature: 130° C.;    -   Pulse width: 450;    -   Pulse repetition period: 4 s; and    -   Cumulative frequency: 10,000 times

In the present invention, the stereoregularity index ([mm]) isdetermined from the mesotriad fraction ([mm]) of propylene chainsobtained by measuring ¹³C-NMR spectrum thereof under the same conditionsas described above using the above ¹³C-NMR apparatus “JNM-EX400 Model”available from Nippon Denshi Co., Ltd.

The larger stereoregularity index ([mm]) means a higher stereoregularityof the polymer.

The propylene-based polymer 1 of the present invention has astereoregularity index ([mm]) of 50 to 90 mol % and preferably 50 to 80mol %.

If the stereoregularity index ([mm]) is less than 50 mol %, theresultant polymer tends to suffer from stickiness. If thestereoregularity index ([mm]) is more than 90 mol %, the resultantpolymer tends to be deteriorated in fabricability.

Here, the mesopentad fraction (mmmm) is preferably 20 to 80 mol % andmore preferably 30 to 70 mol %.

If the mesopentad fraction (mmmm) is less than 20 mol %, the resultantpolymer tends to suffer from stickiness. If the mesopentad fraction(mmmm) is more than 80 mol %, the resultant polymer tends to bedeteriorated in fabricability.

Whereas, the propylene-based polymer 2 of the present inventionsatisfies the following requirements (1′) to (3′) in addition to theabove requirements (1) to (3).

-   -   (1′) an intrinsic viscosity [η] of 0.1 to 0.4 dL/g as measured        in a tetralin solvent at 135° C.;    -   (2′) a crystalline resin having a melting point (Tm−D) of 60 to        120° C., the melting point being defined as a top of a peak        observed on a highest-temperature side in a melting endothermic        curve obtained by a differential scanning calorimeter (DSC) when        a sample is held in a nitrogen atmosphere at −10° C. for 5 min        and then heated at a temperature rise rate of 10° C./min; and    -   (3′) a mesopentad fraction (mmmm) of 30 to 60 mol %.

The propylene-based polymer 2 of the present invention has an intrinsicviscosity [η] of 0.1 to 0.4 dL/g as measured in a tetralin solvent at135° C. The intrinsic viscosity [η] is preferably 0.2 to 0.4 dL/g andmore preferably 0.2 to 0.3 dL/g.

If the intrinsic viscosity [η] is less than 0.1 dL/g, the resultantpolymer tends to be insufficient in strength. For example, when thepolymer is used as an adhesive, the resultant adhesive tends to bebroken and deteriorated in adhesion strength.

If the intrinsic viscosity [η] exceeds 0.4 dL/g, the resultant polymertends to be increased in melt viscosity, resulting in deterioration inmoldability and processability. For example, when the polymer is used asan adhesive, the resultant adhesive tends to be deteriorated incoatability in a molten state owing to its high viscosity. Further, theadhesive tends to be deteriorated in adhesion strength at the bondedinterfacial surface due to its poor flowability.

The propylene-based polymer 2 of the present invention must be acrystalline resin having a melting point (Tm−D) of 60 to 120° C. asmeasured by differential scanning calorimeter (DSC) in view of a goodsoftness thereof. The melting point (Tm−D) of the propylene-basedpolymer 2 is preferably 60 to 100° C. and more preferably 70 to 100° C.

If the melting point (Tm−D) is less than 60° C., the resultantpropylene-based polymer 2 tends to be deteriorated in heat resistance.If the melting point (Tm−D) is more than 100° C., the resultantpropylene-based polymer 2 tends to be increased in melt viscosity,resulting in poor tenacity.

The propylene-based polymer 2 of the present invention has a mesopentadfraction (mmmm) of 30 to 60 mol %, preferably 30 to 50 mol % and morepreferably 35 to 50 mol %.

If the mesopentad fraction (mmmm) is less than 30 mol %, the resultantpolymer tends to be deteriorated in crystallinity and suffer fromstickiness. If the mesopentad fraction (mmmm) is more than 50 mol %, theresultant polymer tends to show a too high crystallinity and bedeteriorated in tenacity, resulting in undesired increase in meltviscosity thereof.

Also, the propylene-based polymer 2 of the present invention preferablyhas a stereoregularity index ([mm]) of 50 to 80 mol %, more preferably50 to 70 mol % and still more preferably 50 to 65 mol %.

The propylene-based polymers 1 and 2 according to the present inventionfurther satisfy, in addition to the above requirements (1) to (3) and(1′) to (3′), (4) a molecular weight distribution (Mw/Mn) of 4 or loweras measured by gel permeation chromatography (GPC), and (5) aweight-average molecular weight of 10,000 to 100,000 as measured by GPC.

The molecular weight distribution (Mw/Mn) as measured by GPC ispreferably 3.5 or lower and more preferably 3.0 or lower.

If the molecular weight distribution (Mw/Mn) is more than 4.0, theresultant polymer tends to suffer from stickiness.

Also, the weight-average molecular weight as measured by GPC ispreferably 10,000 to 50,000 and more preferably 20,000 to 40,000.

If the weight-average molecular weight (Mw) is less than 10,000, theresultant polymer tends to suffer from stickiness.

Whereas, if the weight-average molecular weight (Mw) is more than100,000, the resultant polymer tends to be deteriorated in flowability,resulting in poor moldability.

Meanwhile, the molecular weight distribution (Mw/Mn) is calculated fromthe weight-average molecular weight Mw and number-average molecularweight Mn which are measured by GPC using the following apparatus andconditions:

-   -   GPC measuring apparatus        -   Column: TOSO GMHHR-H(S)HT        -   Detector: RI Detector “WATERS 150C” for liquid chromatogram    -   Measuring conditions:        -   Solvent: 1,2,4-trichlorobenzene;        -   Measuring temperature: 145° C.;        -   Flow rate: 1.0 mL/min;        -   Sample concentration: 2.2 mg/mL;        -   Amount charged: 160 μL;        -   Calibration curve: Universal Calibration; and        -   Analytic program: HT-GPC (Ver. 10)

When the propylene-based polymer of the present invention is in the formof a copolymer, the copolymer is preferably a random copolymer.

In addition, the content of structural units derived from propylene inthe resultant propylene-based polymer is preferably 90 mol % or higherand more preferably 95 mol % or higher.

If the content of structural units derived from propylene is less than90 mol %, the resultant propylene-based polymer tends to suffer fromstickiness on a surface of the obtained molded articles and bedeteriorated in transparency.

When the propylene-based polymer is in the form of a copolymer, theα-olefin content in the copolymer is calculated from ¹³C-NMR spectrummeasured using an NMR apparatus “JNM-EX400 Model” available from NipponDenshi Co., Ltd., under the following conditions.

-   -   Sample concentration: 220 mg/3 mL of NMR solution;    -   NMR solution: mixed solvent of 1,2,4-trichlorobenzene and        benzene-d6 (volume ratio: 90:10);    -   Measuring temperature: 130° C.;    -   Pulse width: 45°;    -   Pulse repetition period: 10 s; and    -   Cumulative frequency: 4,000 times.

When the propylene-based polymer of the present invention is in the formof a propylene homopolymer, the homopolymer may be suitably produced bythe above method (a).

Also, when the propylene-based polymer of the present invention is inthe form of a copolymer, the copolymer may be suitably produced by theabove method (a′).

[3] Propylene-Based Modifier

The propylene-based modifier of the present invention is made of theabove propylene-based polymer.

The propylene-based modifier of the present invention can exhibit a lowmelting point, a good softness and a less stickiness, and can provide amolded article that are excellent in compatibility with polyolefinresins.

Namely, the propylene-based modifier of the present invention iscomposed of the specific propylene homopolymer or propylene-basedcopolymer as described above, and especially contains a slight amount ofcrystalline portions in polypropylene chain moieties thereof. As aresult, the propylene-based modifier of the present invention exhibits aless stickiness and is excellent in compatibility as compared toconventional modifiers such as soft polyolefin resins.

Further, the propylene-based modifier of the present invention isexcellent in compatibility with polyolefin-based resins, in particular,polypropylene-based resins.

As a result, the propylene-based modifier of the present invention isprevented from undergoing deteriorated surface properties such asstickiness, and exhibits a high transparency as compared to conventionalmodifiers such as ethylene-based rubbers.

In view of the above advantageous properties, the propylene-basedmodifier of the present invention can be suitably used as a modifier forimproving physical properties such as flexibility and transparency.

Furthermore, the propylene-based modifier of the present invention mayalso be suitably used as a modifier for improving heat sealability andhot tackiness.

[4] Hot-melt Adhesive Composition

Further, according to the present invention, there is provided anadhesive composition containing the highly flowable propylene-basedpolymer.

The hot-melt adhesive composition of the present invention comprises 99to 50% by weight of the highly flowable propylene-based polymer and 50to 1% by weight of a tackifier resin, and preferably comprises 60 to 90%by weight of the highly flowable propylene-based polymer and 40 to 10%by weight of a tackifier resin.

In addition, the hot-melt adhesive composition of the present inventionmay also contain a viscosity modifier, if required.

If the content of the highly flowable propylene-based polymer is lessthan 50% by weight and the content of the tackifier resin is more than50% by weight, the resultant composition tends to be deteriorated inadhesion strength.

Examples of the tackifier resin used in the hot-melt adhesivecomposition of the present invention include rosin resins prepared fromraw turpentine, terpene resins prepared from raw materials such asα-pinene and β-pinene obtained from pine essential oils, petroleumresins obtained by polymerizing unsaturated hydrocarbon-containingfractions by-produced upon thermal cracking of petroleum naphtha, andhydrogenated products thereof.

Examples of the commercially available tackifier resin include “I-MARBP-125”, “I-MARB P-100” and “I-MARB P-90” all available from IdemitsuPetrochemical Co., Ltd., “ESCOLET 5300” and “ESCOLET 2101” availablefrom Exxon Corp., “HILET T1115” available from Mitsui Chemical Inc.,“CLEARONE K100” available from Yasuhara Chemical Co., Ltd., “ECR227”available from Tonex Co., Ltd., “ARCON P100” available from ArakawaChemical Co., Ltd., and “Regasrez 1078” available from Hercules Inc.

Meanwhile, the tackifier resins are preferably used in the form ofhydrogenated products thereof in view of compatibility with the basepolymer.

Of these resins, more preferred are hydrogenated products of petroleumresins because of excellent thermal stability thereof.

In the present invention, various additives such as plasticizers,inorganic fillers and antioxidants may be blended in the adhesivecomposition, if required.

Examples of the plasticizers include waxes, paraffin-based process oils,naphthene-based process oils, phthalic acid esters, adipic acid esters,aliphatic acid esters, glycols, and epoxy-based high-molecularplasticizers.

Specific examples of the waxes include animal and plant waxes, carnaubawaxes, candelilla waxes, Japan waxes, beeswaxes, mineral waxes,petroleum waxes, paraffin waxes, microcrystalline waxes, petrolactamwaxes, polyethylene waxes, polyethylene oxide waxes, polypropylenewaxes, polypropylene oxide waxes, higher fatty acid waxes, higher fattyacid ester waxes, and Fischer-Tropsch waxes.

Examples of the inorganic fillers include clay, talc, calcium carbonateand barium carbonate.

Examples of the antioxidants include phosphorus-based antioxidants suchas tris-nonylphenyl phosphite, distearylpentaerythritol dip hosphite,“ADEKASTAB 1178” available from Asahi Denka Co., Ltd., “SUMIRISER TNP”available from Sumitomo Chemical Co., Ltd., “IRGAPHOS 168” availablefrom Ciba Specialty Chemicals Corp., and “Sandtab P-EPQ” available fromSand Co., Ltd.; phenol-based anti-oxidants such as2,6-di-t-butyl-4-methyl phenol,n-octadecyl-3-(3′,5′-di-t-butyl-4′-hydroxyphenyl)propionate, “SUMIRISERBHT” available from Sumitomo Chemical Co., Ltd., and “IRGANOX 1010”available from Ciba Specialty Chemicals Corp.; and sulfur-basedanti-oxidants such as dilauryl-3,3′-thiodipropionate, pentaerythritoltetrais(3-laurylthiopropionate), “SUMIRISER TPL” available from SumitomoChemical Co., Ltd., “YOSHINOX DLTP” available from Yoshitomi SeiyakuCo., Ltd., and “ANTIOX L” available from Nippon Yushi Co., Ltd.

(Process for Production of Hot-Melt Adhesive Composition)

The hot-melt adhesive composition of the present invention may beproduced by dry-blending 50 to 99% by weight of the highly flowablepropylene-based polymer, 50 to 1% by weight of the tackifier resin, andvarious optional additives usable according to requirements, with eachother using a Henschel mixer, and then melt-kneading the resultantmixture using a single- or twin-screw extruder, a plastomill or aBanbury mixer.

Examples of the additives optionally added to the composition includethe above plasticizers, inorganic fillers and antioixdants.

The present invention will be described in more detail by reference tothe following examples. However, it should be noted that the followingexamples are only illustrative and not intended to limit the inventionthereto.

First, methods for evaluating resin properties of the propylene-basedpolymers obtained by the production process of the present invention areexplained.

(1) Measurement of Mesopentad Fraction and Stereoregularity Index

Measured by the methods described in the present specification.

(2) Measurement of Intrinsic Viscosity [η]

The intrinsic viscosity of the polymer was measured at 135° C. in atetralin solvent using an automatic viscometer “VMR-053 Model” availablefrom Rigosha Co., Ltd.

(3) Measurement of Weight-Average Molecular Weight (Mw) and MolecularWeight Distribution (Mw/Mn)

Measured by the method described in the present specification.

(4) DSC Measurement (Measurement of Melting Point: Tm−D)

Measured by the method described in the present specification.

More specifically, using a differential scanning calorimeter “DSC-7”available from Perkin Elmer Corp., 10 mg of a sample was held in anitrogen atmosphere at −10° C. for 5 min, and then heated at atemperature rise rate of 10° C./min to prepare a melting endothermiccurve thereof. The melting point (Tm−D) was defined as a top of a peakobserved on the highest-temperature side in the thus prepared meltingendothermic curve.

EXAMPLE 1

(1) Production of Catalyst: Production of (1,2′-dimethylsilylene)

(2,1′-dimethylsilylene)-bis(3-trimethylsilylmethylindenyl)zirconiumdichloride

In a Schlenk bottle, 3.0 g (6.97 mM) of a lithium salt of(1,2′-dimethylsilylene) (2,1′-dimethylsilylene)-bis(indene) wasdissolved in 50 mL of THF (tetrahydrofuran), and the resultant solutionwas cooled to −78° C.

Then, 2.1 mL (14.2 mM) of iodomethyl trimethylsilane was slowly droppedto the solution, and the mixture was stirred at room temperature for 12h.

The resultant reaction solution was distilled to remove the solventtherefrom, and then after adding 50 mL of ether thereto, the reactionsolution was washed with a saturated ammonium chloride solution.

An organic phase separated from the solution was dried to remove thesolvent therefrom, thereby obtaining 3.04 g (5.88 mM) of(1,2′-dimethylsilylene)(2,1′-dimethylsilylene)-bis(3-trimethylsilylmethylindene) (yield:84%).

Next, a Schlenk bottle was charged with 3.04 g (5.88 mM) of the thusobtained (1,2′-dimethylsilylene)(2,1′-dimethylsilylene)-bis(3-trimethylsilylmethylindene) and 50 mL ofether under a nitrogen flow.

After the contents of the bottle were cooled to −78° C., 7.6 mL of ahexane solution of n-BuLi (1.54M; 1.7 mM) was dropped thereto. Thetemperature of the resultant mixture was raised to room temperature, andthen stirred at room temperature for 12 h. Then, the ether was distilledaway from the reaction mixture.

The thus obtained solid was washed with 40 mL of hexane to obtain 3.06 g(5.07 mM) of a lithium salt in the form of an ether adduct (yield: 73%).

The results of ¹H-NMR (90 MHz, THF-d₈) measurement of the obtainedproduct were as follows:

δ: 0.04 (s, 18H, trimethylsilyl); 0.48 (s, 12H, dimethylsilylene); 1.10(t, 6H, methyl); 2.59 (s, 4H, methylene); 3.38 (q, 4H, methylene);6.2-7.7 (m, 8H, Ar—H)

The thus obtained lithium salt was dissolved in 50 mL of toluene under anitrogen flow.

After the resultant solution was cooled to −78° C., a suspensionprepared by dispersing 1.2 g (5.1 mM) of zirconium tetrachloride in 20mL of toluene which was previously cooled to −78° C., was dropped intothe solution.

After completion of the dropping, the resultant mixture was stirred atroom temperature for 6 h. The resultant reaction solution was distilledto remove the solvent therefrom. The obtained distillation residue wasrecrystallized with dichloromethane, thereby obtaining 0.9 g (1.33 mM)of (1,2′-dimethylsilylene)(2,1′-dimethylsilylene)-bis(3-trimethylsilylmethylindenyl)zirconiumdichloride (yield: 26%).

The results of ¹H-NMR (90 MHz, CDCl₃) measurement of the obtainedproduct were as follows:

δ: 0.0 (s, 18H, trimethylsilyl); 1.02, 1.12 (s, 12H, dimethylsilylene);2.51 (dd, 4H, methylene); 7.1-7.6 (m, 8H, Ar—H)

(2) Polymerization

A 1 L autoclave previously heat-dried was charged with 400 mL ofheptane, 0.5 mM of triisobutyl aluminum, 0.8 μM of N,N-dimethylanilinium tetrakispentafluorophenyl borate and 0.2 μM of(1,2′-dimethylsilylene)(2,1′-dimethylsilylene)-bis(3-trimethylsilylmethylindenyl)zirconiumdichloride. Further, hydrogen in an amount of 0.2 Pa as well aspropylene were introduced into the autoclave to thereby control a totalpressure of the reaction system to 0.8 MPa under which conditions thepolymerization was conducted at 70° C. for 30 min.

After completion of the polymerization reaction, the resultant reactionproduct was dried under reduced pressure to obtain 110 g of apropylene-based polymer.

As a result, it was confirmed that the thus obtained propylene-basedpolymer had an intrinsic viscosity [η] of 0.43 dL/g, a melting pointTm−D of 86° C., a stereoregularity (mesopentad fraction) (mmmm) of 43mol %, and a stereoregularity index ([mm]) of 62 mol %.

EXAMPLE 2

(1) Polymerization

A 1 L autoclave previously heat-dried was charged with 400 mL ofheptane, 20 mL of buten-1, 0.5 mM of triisobutyl aluminum, 0.8 μM ofN,N-dimethyl anilinium tetrakispentafluorophenyl borate and 0.2 μM of(1,2′-dimethylsilylene)(2,1′-dimethylsilylene)-bis(3-trimethylsilylmethylindenyl)zirconiumdichloride as produced in EXAMPLE 1. Further, hydrogen in an amount of0.2 Pa as well as propylene were introduced into the autoclave tothereby control a total pressure of the reaction system to 0.8 MPa underwhich conditions the polymerization was conducted at 70° C. for 15 min.

After completion of the polymerization reaction, the resultant reactionproduct was dried under reduced pressure to obtain 57 g of apropylene-based polymer.

As a result, it was confirmed that the thus obtained propylene-basedpolymer had an intrinsic viscosity [η] of 0.41 dL/g, a 1-butene contentof 8 mol %, a melting point Tm−D of 50° C., and a stereoregularity index([mm]) of 63 mol %.

EXAMPLE 3

(1) Polymerization

A 1 L autoclave previously heat-dried was charged with 400 mL ofheptane, 10 mL of 1-octene, 0.5 mM of triisobutyl aluminum, 0.8 μM ofdimethyl anilinium tetrakispentafluorophenyl borate and 0.2 μM of(1,2′-dimethylsilylene)(2,1′-dimethylsilylene)-bis(3-trimethylsilylmethylindenyl)zirconiumdichloride as produced in EXAMPLE 1. Further, hydrogen in an amount of0.2 Pa as well as propylene were introduced into the autoclave tothereby control a total pressure of the reaction system to 0.8 MPa underwhich conditions the polymerization was conducted at 70° C. for 30 min.

After completion of the polymerization reaction, the resultant reactionproduct was dried under reduced pressure to obtain 35 g of apropylene-based polymer.

As a result, it was confirmed that the thus obtained propylene-basedpolymer had an intrinsic viscosity [η] of 0.42 dL/g, a 1-octene contentof 4 mol %, a melting point Tm−D of 49° C., and a stereoregularity index([mm]) of 61 mol %.

COMPARATIVE EXAMPLE 1

The same procedure as in EXAMPLE 1 was repeated except for replacing 0.8μM of N,N-dimethyl anilinium tetrakispentafluorophenyl borate with 0.2mM of methyl aluminoxane. The polymerization reaction was conducted for30 min and the resultant reaction product was dried in the same manneras in EXAMPLE 1, thereby obtaining 5 g of a propylene-based polymer.

As a result, it was confirmed that the thus obtained propylene-basedpolymer had an intrinsic viscosity [η] of 0.7 dL/g, a melting point Tm−Dof 70° C., a stereoregularity (mesopentad fraction) (mmmm) of 44 mol %,and a stereoregularity index ([mm]) of 62 mol %.

EXAMPLE 4

(1) Polymerization

A 10 L autoclave previously heat-dried was charged with 4,000 mL ofheptane, and then evacuated. Thereafter, hydrogen in an amount of 0.5MPa and then propylene were introduced into the autoclave, and thereaction system was heated and pressurized until reaching thepolymerization temperature of 80° C. and the total pressure of 0.8 MPa.

Next, the autoclave was further charged with 5 mM of triisobutylaluminum, 25 μM of N,N-dimethyl anilinium tetrakispentafluorophenylborate and 5 μM of (1,2′-dimethylsilylene)(2,1′-dimethylsilylene)-bis(3-trimethylsilylmethylindenyl)zirconiumdichloride as produced in EXAMPLE 1, and then the polymerization wasconducted for 60 min.

After completion of the polymerization reaction, the resultant reactionproduct was dried under reduced pressure to obtain 1.1 kg of apropylene-based polymer.

Resin properties and physical properties of the thus obtainedpropylene-based polymer are shown in Table 1-1.

EXAMPLE 5

(1) Polymerization

A 10 L autoclave previously heat-dried was charged with 4,000 mL ofheptane, and then evacuated. Thereafter, hydrogen in an amount of 0.3MPa and then propylene were introduced into the autoclave, and thereaction system was heated and pressurized until reaching thepolymerization temperature of 80° C. and the total pressure of 0.8 MPa.

Next, the autoclave was further charged with 5 mM of triisobutylaluminum, 10 μM of N,N-dimethyl anilinium tetrakispentafluorophenylborate and 2 μM of (1,2′-dimethylsilylene)(2,1′-dimethylsilylene)-bis(3-trimethylsilylmethylindenyl)zirconiumdichloride as produced in EXAMPLE 1, and then the polymerization wasconducted for 45 min.

After completion of the polymerization reaction, the resultant reactionproduct was dried under reduced pressure to obtain 1.8 kg of apropylene-based polymer.

Resin properties and physical properties of the thus obtainedpropylene-based polymer are shown in Table 1-1.

EXAMPLE 6

(1) Polymerization

A 10 L autoclave previously heat-dried was charged with 4,000 mL ofheptane, and then evacuated. Thereafter, hydrogen in an amount of 0.2MPa and then propylene were introduced into the autoclave, and thereaction system was heated and pressurized until reaching thepolymerization temperature of 80° C. and the total pressure of 0.8 MPa.

Next, the autoclave was further charged with 5 mM of triisobutylaluminum, 5 μM of N,N-dimethyl anilinium tetrakispentafluorophenylborate and 1 μM of (1,2′-dimethylsilylene)(2,1′-dimethylsilylene)-bis(3-trimethylsilylmethylindenyl)zirconiumdichloride as produced in EXAMPLE 1, and then the polymerization wasconducted for 60 min.

After completion of the polymerization reaction, the resultant reactionproduct was dried under reduced pressure to obtain 1.4 kg of apropylene-based polymer.

Resin properties and physical properties of the thus obtainedpropylene-based polymer are shown in Table 1-1.

EXAMPLE 7

(1) Polymerization

A 10 L autoclave previously heat-dried was charged with 4,000 mL ofheptane, and then evacuated. Thereafter, hydrogen in an amount of 0.1MPa and then propylene were introduced into the autoclave, and thereaction system was heated and pressurized until reaching thepolymerization temperature of 80° C. and the total pressure of 0.8 MPa.

Next, the autoclave was further charged with 5 mM of triisobutylaluminum, 10 μM of N,N-dimethyl anilinium tetrakispentafluorophenylborate and 2 μM of (1,2′-dimethylsilylene)(2,1′-dimethylsilylene)-bis(3-trimethylsilylmethylindenyl)zirconiumdichloride as produced in EXAMPLE 1, and then the polymerization wasconducted for 30 min.

After completion of the polymerization reaction, the resultant reactionproduct was dried under reduced pressure to obtain 1.5 kg of apropylene-based polymer.

Resin properties and physical properties of the thus obtainedpropylene-based polymer are shown in Table 1-2.

EXAMPLE 8

(1) Production of Catalyst: Production of (1,2′-dimethylsilylene)

(2,1′-dimethylsilylene)(3-trimethylsilylmethylindenyl)zirconiumDichloride

A 200 mL Schlenk bottle was charged with 50 mL of ether and 3.5 g (10.2mM) of (1,2′-dimethylsilylene) (2,1′-dimethylsilylene)bisindene under anitrogen flow. After the contents of the bottle were cooled to −78° C.,12.8 mL of a hexane solution containing 1.60 M/L of n-butyl lithium(n-BuLi) was dropped thereto.

The resultant reaction mixture was stirred at room temperature for 8 h,and then the solvent was distilled away therefrom. The obtained solidwas dried under reduced pressure to obtain 5.0 g of a white solid.

The white solid was dissolved in 50 mL of tetrahydrofuran (THF), andthen 1.4 mL of iodomehyltrimethylsilane was dropped to the resultantsolution at room temperature.

Next, the resultant reaction solution was mixed and hydrolyzed with 10mL of water, and an organic phase thereof was extracted with 50 mL ofether. The thus extracted organic phase was then dried to distil off thesolvent therefrom.

After adding 50 mL of ether to the obtained residue, 12.4 mL of a hexanesolution containing 1.60 M/L of n-BuLi was dropped thereto at −78° C.The resultant reaction solution was heated to room temperature andstirred for 3 h to distil off the ether therefrom.

The obtained solid was washed with 30 mL of hexane and then dried underreduced pressure to obtain a white solid.

Then, 5.11 g of the thus obtained white solid was suspended in 50 mL oftoluene, and then mixed with a slurry separately prepared by suspending2.0 g (8.60 mM) of zirconium tetrachloride in 10 mL of toluene inanother Schlenk bottle.

The obtained suspension was stirred at room temperature for 12 h, andthe solvent was distilled away therefrom. Then, the obtained residue waswashed with 50 mL of hexane, and then recrystallized with 30 mL ofdichloromethane to obtain 1.2 g of yellow fine crystals (yield: 25%).

¹H-NMR (90 MHz, CDCl₃): δ-0.09 (S, trimethylsilyl, 9H); 0.89, 0.86,1.03, 1.06 (s, dimethylsilylene, 12H); 2.20, 2.65 (d, methylene, 2H);6.99 (s, CH, 1H); 7.0-7.8 (m, Ar—H, 8H)

(2) Polymerization

A 10 L autoclave previously heat-dried was charged with 4,000 mL ofheptane, and then evacuated. Thereafter, hydrogen in an amount of 0.1MPa and then propylene were introduced into the autoclave, and thereaction system was heated and pressurized until reaching thepolymerization temperature of 80° C. and the total pressure of 0.8 MPa.

Next, the autoclave was further charged with 5 mM of triisobutylaluminum, 5 μM of N,N-dimethyl anilinium tetrakispentafluorophenylborate and 1 μM of (1,2′-dimethylsilylene)(2,1′-dimethylsilylene)-bis(3-trimethylsilylmethylindenyl)zirconiumdichloride as produced in EXAMPLE 1, and then the polymerization wasconducted for 90 min.

After completion of the polymerization reaction, the resultant reactionproduct was dried under reduced pressure to obtain 2.1 kg of apropylene-based polymer.

Resin properties and physical properties of the thus obtainedpropylene-based polymer are shown in Table 1-2.

EXAMPLE 9

(1) Polymerization

A 10 L autoclave previously heat-dried was charged with 4,000 mL ofheptane, and then evacuated. Thereafter, hydrogen in an amount of 0.3MPa and then propylene were introduced into the autoclave, and thereaction system was heated and pressurized until reaching thepolymerization temperature of 80° C. and the total pressure of 0.8 MPa.

Next, the autoclave was further charged with 5 mM of triisobutylaluminum, 5 μM of N,N-dimethyl anilinium tetrakispentafluorophenylborate and 1 μM of (1,2′-dimethylsilylene)(2,1′-dimethylsilylene)-bis(3-trimethylsilylmethylindenyl)zirconiumdichloride as produced in EXAMPLE 1, and then the polymerization wasconducted for 90 min.

After completion of the polymerization reaction, the resultant reactionproduct was dried under reduced pressure to obtain 1.3 kg of apropylene-based polymer.

Resin properties and physical properties of the thus obtainedpropylene-based polymer are shown in Table 1-2. TABLE 1-1 Example 4Example 5 Example 6 Mesopentad fraction (mol %) 39 42 42 Abnormalinsertion content 0 0 0 (mol %) Stereoregularity index (mol %) 54 58 58[η] (dL/g) 0.11 0.17 0.31 Mw × 10⁴ 1.3 1.5 3.0 Mw/Mn 1.9 2.1 2.0 Tm - D(° C.) 72 79 78 ΔH (J/g) 19 25 25

TABLE 1-2 Example 7 Example 8 Example 9 Mesopentad fraction (mol %) 4147 44 Abnormal insertion content 0 0 0 (mol %) Stereoregularity index(mol %) 57 65 61 [η] (dL/g) 0.33 0.35 0.24 Mw × 10⁴ 3.4 3.8 2.3 Mw/Mn1.8 1.8 1.9 Tm - D (° C.) 74 95 98 ΔH (J/g) 26 33 34

The propylene-based polymer obtained in each of Examples 4, 7 and 9, atackifier “I-MARB P-100” available from Idemitsu Petrochemical Co.,Ltd., and a plasticizer “Paraffin Wax 150° F.” available from NipponSeiroh Co., Ltd., were blended with each other in a SUS beaker accordingto the formulation shown in Tables 2-1 and 2-2, and melt-kneaded at 180°C. for 30 min to obtain a hot-melt adhesive composition.

The thus obtained adhesive compositions were evaluated by the followingevaluation methods. The results are shown in Tables 2-1 and 2-2.

[Evaluation Methods]

(1) Melt-Viscosity of Hot-Melt Adhesive

Measured according to JAI-7which is a standard prescribed by Instituteof Japan Adhesive Industry.

-   -   Viscometer: Brookfield-type viscometer    -   Measuring temperature: 180° C.        (2) Adhesion Property of Hot-Melt Adhesive    -   Test specimen: Corrugated board    -   Shape of test specimen: width: 25 mm; length: 100 mm    -   Adhesive-coating temperature: The temperature was controlled        such that the melt viscosity of the adhesive was in the range of        1,000 to 2,000 mPa·s upon coating.    -   Coating amount of adhesive: 3 g/m    -   Open time: 2 sec    -   Setting time: 2 sec    -   Conditioning of test specimen: 3 days at room temperature    -   Breaking method: T-shaped test specimen was rapidly peeled by        hands    -   Testing temperature: 23° C.

Evaluation method: Five test pieces (n=5) was tested for each specimen,and evaluated according to the following ratings.

-   -   A: 4 or more pieces with a break rate of 80% or higher    -   B: 1 to 3 pieces with a break rate of 80% or higher

C: No pieces with a break rate of 80% or higher TABLE 2-1 EvaluationEvaluation Evaluation Example 1 Example 2 Example 3 Blending ratio (%)Propylene-based Example 4 Example 7 Example 9 polymer* 70 70 70Tackifier 30 30 30 Viscosity modifier 0 0 0 Melt-viscosity at 180° C.140 1430 610 (mPa · s) Coating temperature 110 180 160 (° C.) Adhesionproperty at B A A room temperature (break rate: %)Note*Blended with 1000 ppm of antioxidant (IRGANOX 1010)

TABLE 2-2 Evaluation Evaluation Evaluation Example 4 Example 5 Example 6Blending ratio (%) Propylene-based Example 4 Example 7 Example 9polymer* 63 63 63 Tackifier 27 27 27 Viscosity modifier 10 10 10Melt-viscosity at 180° C. 90 660 280 (mPa · s) Coating temperature 100160 120 (° C.) Adhesion property at C A A room temperature (break rate:%)Note*Blended with 1000 ppm of antioxidant (IRGANOX 1010)

INDUSTRIAL APPLICABILITY

According to the present invention, it is possible to produce apropylene-based polymer having a uniform composition, a well-controlledstereoregularity, a high flowability and a high flexibility.

Also, the propylene-based modifier of the present invention can providea molded article having a good softness, a less stickiness, and anexcellent compatibility with polyolefin resins.

Further, the hot-melt adhesive composition of the present invention isexcellent in heat resistance and flowability under high-temperatureconditions as well as adhesion to low-polar substances, and can besuitably used as usable for sanitary materials, packing, bookbinding,fibers, woodworking, electric materials, canmaking, building, bagmaking,etc.

1. A process for producing a highly flowable propylene-based polymer,comprising: polymerizing propylene in the presence of a polymerizationcatalyst comprising: (A) a transition metal compound represented byformula (I):

wherein M is a metal element belonging to Groups 3 to 10 or lanthanoidof the Periodic Table; E¹ and E² are independently a ligand selectedfrom the group consisting of substituted cyclopentadienyl, indenyl,substituted indenyl, heterocyclopentadienyl, substitutedheterocyclopentadienyl, amide group, phosphide group, hydrocarbon groupssilicon-comprising groups, which form a cross-linked structure via A¹and A²; X is a ligand capable of forming a σ-bond wherein when aplurality of X groups are present, said X groups are same or differentfrom each other, and are optionally cross-linked with the other X group,E¹, E² or Y; Y is a Lewis base wherein when a plurality of Y groups arepresent, said Y groups are same or different from each other, and areoptionally cross-linked with the other Y group, E¹, E² or X; A¹ and A²are divalent cross-linking groups capable of bonding the two ligands E¹and E² to each other which are same or different from each other, andare independently a C₁ to C₂₀ hydrocarbon group, a C₁ to C₂₀halogen-comprising hydrocarbon group, a silicon-comprising group, agermanium-comprising group, a tin-comprising group, —O—, —CO—, —S—,—SO₂—, —Se—, —NR¹—, —PR¹—, —P(O)R¹—, —BR¹— or —AlR¹— wherein R¹ is ahydrogen atom, a halogen atom, a C₁ to C₂₀ hydrocarbon group or a C₁ toC₂₀ halogen containing halogen-comprising hydrocarbon group; q is aninteger of 1 to 5 given by the formula: [(valence of M)−2]; and r is aninteger of 0 to 3, and (B) an organoboron compound.
 2. A process forproducing a highly flowable propylene-based polymer, comprising:copolymerizing propylene with ethylene and/or a C₄ to C₂₀ α-olefin inthe presence of a polymerization catalyst comprising: (A) a transitionmetal compound represented by the following general formula (I):

wherein M is a metal element belonging to Groups 3 to 10 or lanthanoidof the Periodic Table; E¹ and E² are independently a ligand selectedfrom the group consisting of substituted cyclopentadienyl, indenyl,substituted indenyl, heterocyclopentadienyl, substitutedheterocyclopentadienyl, amide group, phosphide group, hydrocarbon groupsand comprising groups, which form a cross-linked structure via A¹ andA²; X is a ligand capable of forming a σ-bond wherein when a pluralityof X groups are present, said X groups are same or different from eachother, and are optionally cross-linked with the other X group, E¹, E² orY; Y is a Lewis base wherein when a plurality of Y groups are present,said Y groups are same or different from each other, and are optionallycross-linked with the other Y group, E¹, E² or X; A¹ and A² are divalentcross-linking groups capable of bonding the two ligands E¹ and E² toeach other which are same or different from each other, and areindependently a C₁ to C₂₀ hydrocarbon group, a C₁ to C₂₀halogen-containing hydrocarbon group, a silicon-comprising group, agermanium-comprising group, a tin-comprising group, —O—, —CO—, —S—,—SO₂—, —Se—, —NR¹—, —PR¹—, —P(O)R¹—, —BR¹— or —AlR¹— wherein R¹ is ahydrogen atom, a halogen atom, a C₁ to C₂₀ hydrocarbon group or a C₁ toC₂₀ halogen-comprising hydrocarbon group; q is an integer of 1 to 5given by the formula: [(valence of M)−2]; and r is an integer of 0 to 3,and (B) an organoboron compound.
 3. A highly flowable propylene-basedpolymer wherein the polymer has: (1) an intrinsic viscosity [η] of 0.01to 0.5 dL/g as measured in a tetralin solvent at 135° C.; (2) acrystalline melting point (Tm−D) of 0 to 120° C., wherein the meltingpoint is defined as the top of a peak observed on a highest-temperatureside in a melting endothermic curve obtained by a differential scanningcalorimeter (DSC) when a sample is held in a nitrogen atmosphere at −10°C. for 5 min and then heated at a temperature rise rate of 110° C./min;and (3) a stereoregularity index ([mm]) of 50 to 90 mol %.
 4. Thepolymer according to claim 3, wherein the polymer has: (1′) an intrinsicviscosity [η] of 0.1 to 0.4 dL/g as measured in a tetralin solvent at135° C.; (2′) a crystalline melting point (Tm−D) of 60 to 120° C., themelting point being defined as a top of a peak observed on ahighest-temperature side in a melting endothermic curve obtained by adifferential scanning calorimeter (DSC) when a sample is held in anitrogen atmosphere at −10° C. for 5 min and then heated at atemperature rise rate of 10° C./min; and (3′) a mesopentad fraction(mmmm) of 30 to 60 mol %.
 5. The polymer according to claim 3, whereinsaid polymer further has: (4) a molecular weight distribution (Mw/Mn) of4 or lower as measured by gel permeation chromatography (GPC); and (5) aweight-average molecular weigh of 10,000 to 100,000 as measured by GPC.6. A propylene-based modifier comprising the polymer as claimed in claim3.
 7. A hot-melt adhesive composition comprising 99 to 50% by weight ofthe polymer as claimed in claim 3, and 50 to 1% by weight of atackifier.